To illustrate how the derived expressions can be used, we take the example of an isotropic Heisenberg \(XY\)  model submitted to an external magnetic field. Here, we estimated the temperature and the magnetic field of this quantum Heisenberg model in which the Hamiltonian describing the system can be written as [1]}, [2]}, [3]}, [4]}
\(H=\sum _{n=1}^{2}J\left(S_{n}^{x}S_{n+1}^{x}+S_{n}^{y}S_{n+1}^{y} \right)+B\sum _{n=1}^{2}S_{n}^{z},\) 
